To evaluate the efficacy of low dose megestrol on malnourished dialysis patients we treated 16 dialysis patients with persistent hypoalbuminemia ( < 3.5 gm/dl for 2 consecutive months) and adequate dialysis at a dose of 20 mg orally twice daily. Twelve patients on peritoneal dialysis and 4 on hemodialysis were followed for 4.3 +/- 0.6 m (2-11 m). Within one month serum albumin rose from 2.7 +/- 0.1 to 3.0 +/- 0.2 gm/dl (p < 0.05) and remained elevated at the end of follow-up (3.1 +/- 0.2, p < 0.05 vs. pre-treatment levels). In the 12 responders (increase of albumin > 0.3 gm/dl), all of whom reported improved appetite, the maximal increase of serum albumin in 2 months was 0.8 +/- 0.1 gm/dl (range: 0.3-1.2). Four patients did not respond (change of albumin: -0.05 +/- 0.18, range: -0.6-0.2) because of encephalopathy, amyloidosis, depression or noncompliance. One patient stopped megestrol because of vaginal bleeding from uterine leiomyoma. Three patients died from causes unrelated to the megestrol. Our preliminary study suggests that low dose megestrol (40 mg per day) increases serum albumin levels in 75% of dialysis patients with malnutrition. It is well tolerated but may cause vaginal bleeding from uterine tumors.